Watch with solar cell unit

ABSTRACT

A plurality of pie-shaped solar elements which comprise the face of the watch are positioned and secured by a holder in the form a wagon wheel having two concentric rings joined by a plurality of spokes. The underside of each spoke has a downwardly projecting ridge which extends between adjacent solar elements to separate and locate the elements while providing a cover to hide the edges of each element.

United States Patent Urushida I WATCH WITH SOLAR CELL UNIT June 24, 1975 Primary Examiner-Edith Simmons Jackmon [75] Inventor: Yoshhlsa Urushlda Tokyo Japan Attorney, Agent, or Firm-Sughrue, Rothwell, Mion, [73] Assignee: Citizen Watch Company Limited, Zirm and Ma eak Tokyo. Japan [22] Filed: Mar. 26, I974 [21] Appl. No.: 454,988 [57] ABSTRACT A plurality of pie-shaped solar elements which com- [301 Foreign Apphcauon Pnomy Dam prise the face of the watch are positioned and secured Mar. 27, I973 Japan 48-36230 by a holder i the f a wagon whee] having two concentric rings joined by a plurality of spokes. The [52] U.S. Cl. 58/23 C; 58/127 R underside of each spoke has a downwardly projecting I51] "1- 3,003 G04b 19/06 ridge which extends between adjacent solar elements I58] held of Search 58/23 23 127 R to separate and locate the elements while providing a cover to hide the edges of each element. [56] References Cited UNITED STATES PATENTS 5 Claims, 16 Drawing Figures 3,427.79? 2/1969 Kimura ct al 58/23 BA I L W J R 5 5 /O 7 0 2d. I l I [3a 3 III I n S n \l 538 32 PATENTEDJUN24 ms 3.890.776

sum 1 FIG. I

PATENTE JUN 0 241915 mm 2 1&1140176 PATENTED JUN 2 4 I915 3 l 8 9 O 7 7 6 sum 3 FIG. 7

WATCH WITH SOLAR CELL UNIT This invention relates generally to improvements in and relating to small timepieces, especially watches fitted with solar cell means as an energy source for drive thereof. More specifically, it relates to such an electronic watch fitted with a grouped and unified arrangement of a plurality of solar cell elements and with a po sitioning means for the solar cell unit for definitely and positively positioning at least the outer peripheral margin thereof and a plurality of radially extending marginal gaps defined by and between segmental cell elements, at the front side of the watch.

A modern tendency in the electronic watch industry is such that the watch is fitted as its energy source means with a secondary battery unit and a solar cell unit. The charged energy in the latter is first accumulated in condenser means and then discharged therefrom for the drive of time display means, preferably time-indicating hands. In such watches, the solar cell unit is positioned generally on the watch dial. In the manufacture of the cell elements, they are scribed or cut off from larger stocks by means of a diamond cutter and thus represent rough cut edges and inaccurate overall configuration of the unit assembled together of these elements and uneven dimensions, especially widths of the gaps defined by and between the confronting cell elements.

It is therefore a main object of the invention to provide an electronic watch fitted with a solar cell unit comprising a number of cells which are positioned by an efficient and reliable guiding and positioning means for protecting and covering the overall peripheral region of the unit as well as the radially extending gaps of the above kind.

A further object is to provide the guiding and positioning means of the above kind to improve otherwise caused nonattractive appearance of the solar cell unit caused by the rough finishing and dimensions thereof.

These and further objects, features and advantages of the present invention will become more apparent when reading the following detailed description of the invention with reference to the accompanying drawings illustrative of several preferred embodiments of the present invention.

In the drawings:

FIG. 1 is a plan view of an embodiment of the electronic watch fitted with a solar cell unit wherein, however, the outline configuration of the watch case is shown only schematically by a chain-dotted line and the crystal of the watch has been omitted for a simplitied and clearer representation.

FIG. 2 is an enlarged partial view of the solar cell unit assembly shown in FIG. 1.

FIG. 3 is an enlarged axial section of the electronic watch shown in FIG. 1, taken along a section line III III shown therein, but a part has been omitted from the drawing for simplicity.

FIG. 4 is a still further enlarged axial section of the solar cell unit assembly shown in FIG. I and taken along a section line IV IV shown therein, wherein, however, a part has been omitted from the drawing only for simplification.

FIG. 5 is an enlarged plan view of a cell positioner constituting a member of the solar cell unit assembly shown in the foregoing several figures.

FIG. 6 is a section ofthe cell positioner shown in FIG. 5, taken along a section line VI VI shown therein.

FIG. 7 is an enlarged and inverted plan view of one of the cell elements included in the solar cell unit assembly shown in the foregoing.

FIG. 8 is a reduced sectional view of the cell element shown in FIG. 7 taken along a section line VIII VIII shown therein, the reduction being relative to FIG. 8.

FIG. 9 is an enlarged plan view of a printed circuit board included in the solar cell unit assembly shown in the foregoing.

FIG. 10 is a sectional representation of the printed circuit board shown in FIG. 9, taken along a section line X X shown therein.

FIG. II is an enlarged section taken along a section line XI XI shown in FIG. 2.

FIG. 12 is an enlarged section taken along a section line XII XII shown in FIG. 2.

FIG. 13 is a similar section of a slightly modified structure from that shown in FIG. 12.

FIG. 14 is a similar view to FIG. I3, showing a further slight modification.

FIG. 15 is a plan view of a second embodiment of the solar cell unit positioner, being different from that shown in FIG. 5.

FIG. 16 is a plan view of a third embodiment of the solar cell unit positioner.

In the following, several preferred embodiments of the solar cell unit according to this invention will be described in detail by reference to FIGS. 1 12.

IN FIGS. 1 and 2, showing the first embodiment, numeral 1 represents the solar cell unit assembly having five similar sector-shaped cell elements 20 2e arranged in a concentric manner as shown, and relative to the center of the watch of which only a watch case is shown at 9 in a highly schematic and phantom manner.

Numeral 3 represents an imitation element to one of said cell elements 20 2e, having similar sector outline configuration as shown. Numeral 5 represents a solar cell unit positioner specifically designed for the purpose of the invention. Numeral 6, 7 and 8 represent conventional hour-, minuteand seconds hand, respectively.

Next, referring to FIGS. 4 12, the solar cell unit assembly 1 shown schematically in the foregoing will be illustrated in a more specific manner. The unit assembly 1 comprises the positioner S which is shown more specifically in FIGS. 5 6; five cells 20 2e more specifically shown in FIGS. 7 and 8, the printed circuit board 10 shown more specifically in FIGS. 9 l0 and the imitation element 3.

In FIGS. 7 8, numeral 21 represents a N-type silicon layer; 22 a P-type silicon layer, 23 a reflection prevention layer of silicon oxide; 24 a protecting layer of epoxy resin.

The P-type silicon layer 22 which covers partially the rear (upper in FIG. 8) surface of the cell element shown in FIG. 8 and an anodic electrode 25 made of Au and having a sector shape as shown in FIG. 7 is given on the rear side silicon layer portion by the printing technique. On the rear (upper in FIG. 8) surface of N-type silicon layer 21 is printed only partially with a cathodic electrode 26 again made of Au and having a substantially triangular configuration when seen in FIG. 7. Such structure of the solar cell element is highly known per se and a further analysis of the operation thereof could be omitted from being set forth for easy understanding of the invention.

The cell positioner 5, shown more specifically in FIGS. and 6, is made of epoxy resin and has a wheel type outer ring portion 51 and an inner central ring portion or boss 52. These rings 51 and 52 are rigidly connected with each other by means of a plurality of, herein six, radial rams 53a 53f.

Radial arms 53a 53f and outer ring portion SI are formed on their respective rear or bottom surfaces with downwardly depending shouldered projections or ribs as shown at 530-1 53f-l and 51-], respectively. The inner central ring or boss portion 52 is formed with a depending tubular projection shown at 520, so as to provide a sleeve.

Twelve rivets 54a 54l corresponding to 12 conventional hour indications on the watch dial, are embedded in the material of the outer ring portion 5].

On the rear surface 51-] of said outer ring member 51, there are formed with several recesses 51a 5 Id for avoiding conflict with headed top ends of legs 13 and 12 shown in FIG. 10, as met during assembly job of the outer ring member with the printed circuit board, as will be more fully described hereinafter. Further recesses Slb and 510 are equally formed on the rear surface of said ring member 51 for avoiding later conflict with electrodes l4a-l and 1417-] appearing in FIG. 9. A projection 56 on the upper surface of said ring member 51 serves for a time indicator for "12 oclock."

The material of the printed circuit board shown in FIGS. 9 and 10 is epoxy resin and has generally a disc shape and formed separately with a plurality of openings lla l lw by punching, ofwhich those which are denoted with 11a, llb, lld, 11g 11! and 11:1 Hp are provided for avoidance of interference with said rivets 54a 54!. Openings 11c and He are provided for passing several leads, as at [6, FIG. 3, adapted for connection of several points of the cell unit assembly 2 with other circuit portions, not shown, of the electronic watch movement, not shown.

Those openings which are denoted with llfand 11m are provided for attachment of dial legs 12 and 13, respectively. Those openings which are denoted with llr l Iv are filled with glueing agent during the assembly job to be described. The central opening llq is provided for the passage of a central shaft 17d of the watch movement 17 during the assembly job. A rectangular window opening 11w is adapted for overlapping with a conventional calendar display window 30 formed through the imitation segment 3. Conventional date dial is seen at 31 in FIGS. l and 3 while conventional day dial is seen at 32.

Numeral 14a 14f represent printed electrodes formed on the board 10 for providing proper electric connection with solar cell segments 2a 2e when assembled.

Electrode 140 has generally a sector-shape as shown and is provided with a terminal I4a-l. Electrode 14b has generally a sector-shape as shown and is connected conductively with a terminal l4b-l. Electrodes 14d l4f have each a sector-shape as that of the electrode 140 which represents an outer main portion 140-1 of sector-shape, an inner portion of sector-shape and a I connecting portion lle-3 extending between the both.

As shown in FIG. 4, the positioner 5, five solar cells 2a 2e and the board 10 are assembled together to provide the unit assembly I.

For this purpose, the positioner 5 is overturned up and down from the position shown in FIG. 5, so as to expose the rear or bottom surface thereof. Then, nonconductive epoxy resin adhesive 27 is poured from upper into several shouldered lower level portions exclusive of those denoted 51a 5 Id.

Further. cell segments 2a 2e and the imitation element 3 are brought into their respective positions defined by radial arms 530 53fand by the ring projection being defined as at 51-1, so as to be glued in position.

In this way, all the peripheral rough-machined edge of each of the cell segments is completely hidden by the radial arms and the outer ring of the positioner. This hidden state is clearly seen from the sectional and partial views shown in FIGS. II and 12.

As a representative wiring mode, the lead 16, FIG. 3, is passed through the respective opening llc from below in FIG. 9 to upper to the terminal of the electrode 14a on board 10 and soldered therewith, and

so on.

Next, a conductive adhesive resin is applied onto the surface of each of the electrodes 14a l4fand then the foregoing sub-assembly 2; 3; 5 is placed, so as to provide the complete unit assembly.

Finally, epoxy resin adhesive 15 is filled under pressure into the openings llriiv, so as to intensifying the adhesive attachment of the board 10 with the cell subassembly.

As may be well supposed from the foregoing description, five solar cell elements 20, 2e, 2d, 2c and 2b are electrically connected one after another in series through such current passage route as: 16 14a 2a l4f- 2e l4e 2d 140' 20 14c 2b 14b to the electronic watch movement 17.

As was referred to hereinbefore, first radial arm 53a directs towards 12 oclock, and second radial arm 53b directs towards 2 oclock, and so on.

In FIG. 3, numeral 28 represents a spacer ring which positioned between the assembly 1 and the watch movement 17. The attachment of the assembly I to the movement 17 is made by itilization of legs 12 and 13 and proper lateral set screws, not shown, as conventionally.

The connecting lead 16 extending from the board 10 is fixedly attached by its opposite end to a further printed circuit board which constitutes a member of the watch movement 17, through a screwed-in tapped metallic tube 17b and a set screw 17c threaded into the tapped tube. When the lead [6 acts as a positive conductor, a similar negative conductor, not shown, extending from terminal l4b-l which is electrically connected with inner smaller sector 14b as was referred to, towards the watch movement for the completion of the source power circuit to the latter.

In FIG. 3, numeral l8 shows partially the crystal glass of the watch and numeral 19 represents bezel therefor, while 20 shows case band of the watch case 9.

Numeral 21 represents back cover of the watch and is detachably attached to case band 20 by means of an attaching ring 22. These members 18 22 are naturally of known structure and arrangement.

Numeral 23 represents an inside frame mounting the watch movement I7 in cooperation with bezel I9 and being in turn mounted on the case band 20.

The positioner 5 is shown as made of an insulating resin material, but if necessary, it may be prepared with a metallic material. In the latter case, however, the surface, especially those surface regions adapted for contacting with the solar cell elements must beforehand be subjected to a proper insulation treatment known per se.

If necessary, the positioner 5 may be fixedly attached to the board 10 as by rivetting at 54a 541.

The material of positioner 5 may be of transparent of opaque nature, as the case may be. In the former case, the upper surface can be be finely serrated as shown in FIG. 13 for obtaining an opaque characteristic. By adopting a lense-like cover as at 253 in FIG. 14, a similar masking effect can be provided. Several constituents shown in FIG. 13, each related numeral shown in FIG. 12 has been added with I00 for clear understanding thereof. In FIG. 14, similar addition of 200 has been made.

In FIG. 15, the second embodiment of the positioner is shown at 305. In this embodiment, the imitation element 3 has been omitted. For this purpose, the positioner 305 is integrally formed with a sector-shaped covering portion 355. Other constituents have been shown by adopting same reference numerals as employed in the first embodiment, each time being added with 300 for better identification. The sector 355 may be formed along its straight radial edges with proper projections as was employed in the first embodiment as at 53a-l 53f-l.

In the third embodiment shown in FIG. 16, the positioner 405 has been shaped into a square configuration so as to cover and protect a similarly formed solar cell unit assembly, not shown. Several constituting members are shown with respective same references as was used in the first embodiment, each time being however added with 400 for quicker identification.

What is claimed is:

I. In an electronic watch of the type having a solar cell unit comprised of a plurality of separate spaced apart solar cell elements positioned in place of a conventional time display dial. the improvement comprising the provision of a protecting and positioning means for covering the edges of each cell element and separating said elements from each other. said protecting and positioning means comprising an inner ring portion, a plurality of radially extending arms spanning the space between adjacent cell elements and partially overlying the outer surfaces of said cell elements adjacent the edges thereof, an outer peripheral member connecting the outer ends of said arms and partially overlying the outer surfaces of said cell elements along the outer periphery thereof and a dependent rib on the under surface of each of said arms extending in between said cell elements.

2. In an electronic watch as set forth in claim 1 further comprising an imitation cell element having a shape similar to said solar cell elements disposed between two solar cell elements and having an aperture therein for viewing a standard calander display.

3. In an electronic watch as set forth in claim 1 wherein said protecting and positioning means is formed with a covering portion extending between and integrally connected with adjacent arms and having an aperture therein for viewing a standard calander display.

4. In an electronic watch as set forth in claim I wherein each of said solar cell elements has a sectorshaped configuration and said outer peripheral member is ring-shaped.

5. In an electronic watch as set forth in claim I wherein each of said solar cell elements has a rectangular configuration and said outer peripheral member has a rectangular configuration. 

1. In an electronic watch of the type having a solar cell unit comprised of a plurality of separate spaced apart solar cell elements positioned in place of a conventional time display dial, the improvement comprising the provision of a protecting and positioning means for covering the edges of each cell element and separating said elements from each other, said protecting and positioning means comprising an inner ring portion, a plurality of radially extending arms spanning the space between adjacent cell elements and partially overlying the outer surfaces of said cell elements adjacent the edges thereof, an outer peripheral member connecting the outer ends of said arms and partially overlying the outer surfaces of said cell elements along the outer periphery thereof and a dependent rib on the under surface of each of said arms extending in between said cell elements.
 2. In an electronic watch as set forth in claim 1 further comprising an imitation cell element having a shape similar to said solar cell elements disposed between two solar cell elements and having an aperture therein for viewing a standard calander display.
 3. In an electronic watch as set forth in claim 1 wherein said protecting and positioning means is formed with a covering portion extending between and integrally connected with adjacent arms and having an aperture therein for viewing a standard calander display.
 4. In an electronic watch as set forth in claim 1 wherein each of said solar cell elements has a sector-shaped configuration and said outer peripheral member is ring-shaped.
 5. In an electronic watch as set forth in claim 1 wherein each of said solar cell elements has a rectangular configuration and said outer peripheral member has a rectangular configuration. 